Obesity and Type 2 diabetes are major health problems contributing to morbidity and premature mortality. Occupational sitting time is independently associated with overweight and obesity for full-time workers. Each two hour increment in sitting time at work is associated with a 7% increase in Type 2 diabetes and 5% increase in obesity. Work breaks for full-time employees represent an important, as yet untapped opportunity to incorporate physical activity. Time and productivity loss due to chronic diseases associated with overweight and obesity may make it a cost effective financial investment for employers to promote physical activity at work. What is not known is the extent to which work break practices at the work place can promote health by incorporating physical activity. The broad, long-term objectives of this application are to promote health in the work place through the introduction of physical activity during work breaks. Ten- to-fifteen minutes of physical activity can produce health benefits related to weight and insulin levels. Booster breaks are organized and guided physical activity sessions during a standard 15-minute work break. The proposed research is a 12 month cluster randomized controlled trial with 3 treatment arms: (1) the booster break intervention (N=30); (2) an hourly computer prompt to get up and walk around for 21/2 minutes (N=30); or (3) standard work break practices (e.g., 15 min break in am and pm and 30 min lunch break) (N=30). Fifteen office based work units with similar occupations will be randomly assigned to one of the three conditions. The booster break session will be facilitated by a trained employee at the worksite, every work day during one of the standard am or pm 15-minute work breaks. The specific aims are to: 1) evaluate compliance with the intervention; and 2) compare the treatment arms across outcome measures. The hypotheses are that participants in the booster break sessions will have greater favorable increases in psychological and physical health as well as employee morale compared to booster break non-participants. Outcome measures are changes in blood pressure, insulin level, body mass index, abdominal circumferences, skin fold thickness, physical activity patterns, and organization morale assessed at baseline, six months and one year. Age, gender, racial/ethnic background, occupation, weight status, and health habits (e.g., smoking, drinking, etc.) will be controlled for. If successful, booster breaks may be an effective, low-cost, intervention to counter the current trends of increasing sedentary behavior, increasing weight, and the resultant increase in morbidity in the United States population. The relevance of this research to public health is that the booster break innovation has the potential to reach large numbers of people at the workplace. Specifically, the booster break innovation can promote health in the work place by reducing morbidity related to hypertension, diabetes, and obesity. [unreadable] [unreadable] [unreadable] [unreadable]